Saw attachment for electric hand drills



Dec. 15, 1953 c. e. LINDELL. 2,662,562

SAW ATTACHMENT FOR ELECTRIC HAND DRILLS Filed Dec. 27, 1949 2 Sheets-Sheet 1 1 wuwam \uu FIG 4 Jinn! 7111111115 &

INVENTORT QARL G- LINDELL ATTORNEY Dec. 15, 1953 c. G. LINDELL 2,662,562

SAW ATTACHMENT FOR ELECTRIC HAND DRILLS Filed Dec. 27, 1949 2 Sheets-Sheet 2 FIG 8 FIG I4 55 INVENTOR. CARL G. LINDELL ATTORNEY Patented Dec. 15, 1953 UNITED STATES (IFFICE SAW ATTACHMENT FORELEGTRIO HAND: DRILIJS Carl G. Lind'ell; Minneapolis, Minn;-

Applicationflccemben 27, 1949-, Scrial-No..135,181

2' Claims; (01. 143-43) present, invention relates to improvements. in cutting. attachments for hand drills. of. the typedi'sclosed in. my pending Unitedv States application for patent for Boring. Attachment for a Hand Drill, filed December 9, 1946, under Serial. No. 714,979, new Patent l-lo ..2,57 ,589

It is well known that. in installing elcctri'cwires, it isnow mandatory in a great many instances, by city ordinance or otherwise, to place electric wires in rigid conduits in placecf flexible casingsas hereto has been. the general practice. These flexible casings were installed by threading the same through holes bored. in timbers or other. parts. In installing rigid conduits in buildings, it is necessary to cut notches in. the joist, studding or other parts to receive the conduits.

It is, of. course, evident that the invention is; equally well. adapted for use in plumbing and. heating. installations. wherein. it is necessary to notch joists and studclings to receive pipe.

An object of this invention. istoprovide. a novel saw attachment for a hand drill.

Another object. oi this invention is to provide a novel guide for positioning the saw relative to a timber to be cut thereby.

Still another object of thisinvention. istoprovid'e means that controls the depthto which the saw is to cut.

A- further object of. this inventionis to provide a novel coupling for attaching a driven shaft casing. to a hand drill.

Other objects of this invention will be apparent.- from the following description, reference being bad to the drawing.

Tothe above end, generally stated, the invention consists of the novel devices and combination of devices hereinafter described and defined in. the claims- In the accompanying drawing, which illustrates the invention, like. characters. indicate like parts throughout th several views.

Referring to the drawing:

Fig. 1 is a side elevational view of the invention and also showing in section a fragment of aifioor structure that has been sawed by the attachment;

Fig. 2 is a front elevational view of, the invention as shown in Fig. 1

Fig. 3 is a fragmentary detail view partly in elevation and partly in section taken on. the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary view partly in elevationand partly in section taken on the line 4-4, of Fig. 2, on an enlarged scale;

Fig. 5 is a fragmentary detail view in section taken substantially on the line 5-5 of Fig, 4.;

Fig; 6 is" a View corresponding to th upper portion ofthe" invention as shown. in Fig. 2; with the exception thatsome parts are removed and further showing adjustable means for varying the depth of a cut tobemacl'e by the saw;

Fig: 7' is anel'evation'al" View of a bit;

Fig. 8 is a vies/corresponding to the'upper portion of Fig.- 1 and further-showing a combined saw guard and sawdust collector attached to the housing;

Fig; 9 is a front elevationalview of the parts showrrin- Fig. 8

Fig. 1 0* is a rear elevationalview ofthe combined" saw guard and sawdust collector removed fromtheatta'chment;

Figs. 11 and 12 are-top and bottom plan views, respectively, of the combined saw guard and sawdust collector;

Fig. 13' is 9,- fragmentary detailview in side elevation of the combined saw guard and sawdust collector with the cover partly open; and

Fig. 14* is a view in transverse section taken on the line M M of Fig. 10 onan enlarged scale.

The numeral T indicates a conventional hand drill, an entirety; with the exception of the annular outer endportion of its housing 8, of reduced. diam'eterand having at its inner end a stop shoulder 9 A chuck F8 is attached to the drive shaft I oi'th'e drill 1 A long driven shaft casing i2 is attached at one end to the drill l by a novel coupling 13 and is of an external diameter somewhat more than the cli'ameterof'the housing end portion 8. The coupling' l3 is in the form of a sleeve, one end por tion of which istelescoped; onto thehousing end portion 8 against the stop shoulder 9 and its other end portion is of a reduced diameter and telescoped onto the respective end portion of the shaft casing 12.. Each end portion of th coupling.- i3; is: longitudinally slit at M and integral with each end portion is a pair of laterally spaced ears t5 between which the slit extends. A screw I 6: extends: loosely through one of. the ears! 5 and has screw-threaded; engagement with the other thereof. Obviously, by tightening the screws [6, the. end portions of the coupling it; will be contracted and frictionally clamped onto the housing end portion 8 and the shaft casing i2. This. coupling l3. affords a housing for the chuck it.

On the other end of the. shaft casing 52 is a flat rectangular base, It having at its center 2. depending tubular: shank [8, they outer end portion of which is of slightly decreased diameter and; at the inner end thcreor: is a stop. shoulder I9. This shank: [8; extends into. the respective end portion. of; the shaft casing 2 with a. snug 3 fit and the outer end of said casing is in engagement with the stop shoulder It. A screw 29 detachably secures the shaft casing I2 to the shank It.

A housing 2| is removably mounted on the base 'i and held centered thereon by an annular boss 22 on said base which snugly fits in a round hole in the bottom of the housing 2|. The housing 2| is further detachably secured to the base it by screws 23.

Extending axially through the casing E2 is a long driven shaft 24, the lower end portion of which is held by the chuck for rotation therewith. On the upper end of the shaft 25 is a bevel pinion 25 within the housing 2|. This pinion 25 meshes with a bevel gear 26 having a relatively long hub 21 journaled on the front member 28 of the housing 2|. Extending axially through the gear 26 and its hub 2'? is a sleeve bearing 29. The rear end of the bearing 29 is closed by an end member 38 and formed therein, at the axis thereof, is a hole 3i.

The rear end portion of the bearing 29 and its end member 30 are journaled in a bronze bushing 32, the end portion of which extends through a hole 33 in rear member 34 of the housing 2! and is rigidly held by a pressed fit with said member. The bushing 32 is further secured to the housing member 35 by the head of a screw 35 having threaded engagement with the housing member 34. The head of this screw 55 impinges the outer end of the bushing 32, see Fig. 4, and prevents outward axial movement thereof. The bushing 32, at its inner end, affords a stop for the gear 23.

A circular saw 35 is mounted on an arbor 3'? that extends axially into the bearing 29 from the front end thereof. The saw arbor ST is detachably secured to the hub 2! of the gear to be rotated thereby by a pair of diametrically opposite joints 38. Each joint includes an L- shaped slot 39, in the front end portion of the hub 2? of the gear 26 and the sleeve bearing 29, and the end portions of a pin 45 that extends transversely through the arbor 5'5. The forward edge portions of the hub 21 and the bearing 25, at the lateral portions of the slots 39, are notched at ii and into which the pin 45 extends. The pin 49 is positively held in the notches 4| by a screw 42 which extends through the hole 53, has threaded engagement with the housing member and impinges the rear end of the arbor 3! and prevents axial movement of said arbor in the bearing 29. A shoulder 28' on the gear hub 2'5 engages the inner side of the housing member 23 and prevents outward axial movement.

To position and hold the saw relative to a joist x, on which is laid a floor y, the housing 2| is provided with a guide 43 in the form of a pair of upstanding plates 44. These guide plates 44 are secured one to each side of the housing 2| by screws 45. The guide plates 44, above the housing 2|, are laterally spaced apart to receive the joist a: therebetween and their upper end portions are outwardly curved to facilitate the entrance of said joist therebetween. In Fig. l, a cut 2 has been made in the joist x by the saw 35 and said saw is in a second cut in said joist. At the completion of the two outs in the joist :c, the stock between said cuts is knocked out with a hammer to leave a passageway for a conduit.

The depth of a cut made by the saw 35 may be varied, at will, by an adjustable stop 45. This stop 45,'as shown in Fig. 6, is a rectangular block 4'! on the inner side of one of the guide plates 44 and clamped thereagainst by a screw 48. The screw 48 extends through a washer 45 on the outer side of the respective guide plate 44, through a vertical slot 50 in said plate and has threaded engagement with the stop 46. Obviously, by lifting the device to feed the saw 35 to its work. the stop 45 will be brought into contact with the lower edge of the joist a: and limits the depth of the cut made by the same. In some instances, the stop 46 may be removed and, in which case, the top of the housing 2| will act as a stop.

On the outer side of each guide plate 44 is a reinforcing member 5| in the form of a channel; however. in actual manufacture, this reinforcement will be formed as an integral part of the guide plate 44. Also, in actual manufacture, suitable guards will be provided for the saw 36.

When a flexible conduit is to be used, the saw 355 may be removed and the bit 52, shown in Fig. 7, substituted therefor for boring holes through which the conduit will be threaded. A handle 53 is attached to the shaft casing l2.

Figs. 8 to 14, inclusive, show a combined guard for the saw 35 and a collector for sawdust cut by the saw. This combined saw guard and sawdust collector is in the form of a receptacle 54 that is rectangular in cross-section. The front member of the receptacle 54 affords a cover 55 attached to the bottom member of the receptacle 54 by hinges 56 for outwardly swinging movement. The cover 55 is provided with a capping flange 51 that snugly fits over the receptacle 54. To hold the cover 55 closed, there is secured to the sides of the receptacle 54 a pair of screw studs 58 provided with wing nuts 59. In the sides of the capping flange 51 are V-notches 60 through which the screw studs 58 extend and the wing nuts 59 impinge said capping flange and hold the cover 55 closed.

The saw 36 is encased in the receptacle 54 and the back member of said receptacle extends between the housing front member 28 and the saw 36 and said back member has a hole 6| therein for the saw arbor 31. This receptacle 54 is secured to the front member 28 of the housing 2| by screws 62. The tops of the receptacle 54, the cover 55 and the capping flange 57 are semi-circular and the centers thereof are at the axis of the saw 36. A notch 63 having upwardly diverging sides is formed in the back member of the receptacle 54, the cover 55 and the capping flange 51 to receive the joist a: as the saw 36 is fed thereto in making a cut therein.

Obviously, sawdust cut by the saw 35 will be precipitated into the receptacle 54 and this prevents the same from falling on the operator holding the attachment and particularly into his eyes as he is looking up to watch the work. Sawdust accumulated in the combined saw guard and sawdust collector may be emptied simply by inverting the attachment and thus permitting the sawdust therein to flow therefrom through the open notch 63.

From what has been said, it will be understood that the invention described is capable of various modifications as to details of construction and arrangement within the scope of the invention herein disclosed and claimed.

What I claim is 1. An upright elongated shaft, a housing fixed on the upper end of the shaft, an arbor journaled in the housing perpendicular to the projected axis of the shaft, a circular saw mounted on the arbor outwardly of the housing, means for driving the arbor, a pair of wide side plates secured to the housing perpendicular to the plane of the saw and spaced inwardly thereof, said plates projecting materially above the saw and laterally spaced equi-distances from the projected axis of the shaft, the plates above the housing being transversely flat, and parallel with their extreme upper end portions turned outwardly, and a stop member projecting between the side plates above the housing and attached to one of the side plates for adjustment longitudinally thereof.

2. An upright elongated shaft, a housing fixed on the upper end of the shaft, an arbor journaled in the housing perpendicular to the projected axis of the shaft, a circular saw mounted on the arbor outwardly of the housing, means for driving the arbor, a pair of wide side plates secured to the housing perpendicular to the plane of the saw and spaced inwardly thereof, said plates projecting materially above the saw and laterally spaced equi-distances from the projected axis of the shaft, the plates above the housing being transversely flat and parallel with their extreme upper end portions turned outwardly, and a box-like dust receptacle encasing the saw with its side between the housing and the saw secured to the housing, the outer side of the receptacle being hinged to open and nor mally held closed, said receptacle being completely closed except for a transverse notch in its upper end portion to expose the cutting portion of the saw.

CARL G. LINDELL.

References Cited'in the file of this patent UNITED STATES PATENTS Number Name Date Re. 20,687 Grozier Apr. 5, 1938 1,271,618 Reese July 9, 1918 1,520,330 Chinn Dec. 23, 1924 1,533,974 Davis Apr. 14, 1925 1,785,065 Aborn Dec. 16, 1930 1,806,582 Beutner May 26, 1931 1,999,138 Mason Apr. 23, 1935 2,248,694 Boyette July 8, 1941 2,342,052 7 Jimerson et a1 Feb. 5, 1944 2,490,255 Chase Dec. 6, 1949 2,504,913 Winebrenner Apr. 18, 1950 FOREIGN PATENTS Number Country Date 532,631 France Nov. 18, 1921 

